Plants affected - Apple, Evans Cherry, Hawthorn. Worse on early ripening apples.
- Adults lay eggs in fruit early to mid July. Maggots make trails rendering fruit inedible (outside pockmarked)
- Larvae drop to ground and pupate until the next June - July
- Lay a barrier (landscape fabric, remay cloth) on top of soil under the tree—this prevents pupae from emerging from soil, as well as larvae entering soil in fall.
- Apple Maggot Traps—hang in trees in mid-late May. Traps contain a pheromone to lure adults. Average emergence date in Alberta is July to August.
- DO NOT allow fruit to lay on ground (use tarp or pick daily)
Cherry Fruit Fly
Plants affected - Cherry
Symptoms - Larvae (maggots) feed in the flesh near the pit of cherries rendering them inedible.
- Overwinter as pupae in soil under trees. Five to 9 days after emerging, adult female flies lay eggs singly in cherries.
- Larvae feed for 1-2 weeks then cut exit hole and drop to ground to pupate.
- Adults are present from June through August, generally peaking close to harvest. Flies are weak and will usually not travel farther than the first cherry tree they find.
Cultural Control - Hang yellow sticky traps in late May in trees to monitor fly emergence (for spraying date) and to trap adults.
Plants affected - Red and White Currants (not black), Gooseberry
Symptoms - Leaves stripped from branches; fruit is not affected.
- Female lays eggs on underside of leaf close to ground; young larvae make holes in leaves, as they mature damage becomes more severe; leaves are entirely stripped from shrub.
- Overwinter in soil as a cocoon.
- Examine leaves in May; look for white eggs low down in center of the bush, remove leaves.
- Clear away debris and mulch in the fall, and disturb the soil in spring so birds will find them.
Chemical Control - Not recommended once larvae seen; try to destroy eggs early on.
Plants affected - Saskatoon
- Small scars on upper part of green berries. Larger fruit may have holes.
- Later in season fruit may appear as empty black shells.
- Adults emerge in May, lay eggs on flowers. Eggs hatch, larvae emerge and feed on fruit.
- In late June, larvae drop to ground and overwinter in soil.
Cultural Control - Look for adult sawflies when blooms emerge; hand-pick.
Plants affected - Soft skinned fruits
Symptoms - Clear sap oozing from sides of fruit
Control - Cover smaller trees with remay cloth as fruit is ripening, hang traps filled with sugar water/juice to distract wasps.